The first department can select his pair by 6*5 = 30 ways. The second department can select his pair by 8*7 = 56 ways. The third department can select his pair by 9*8 = 72 ways. These selections are INDEPENDENT, so the total number of ways is the product 30*56*72 = 120960 different ways. ANSWER Notice that in this problem the order in pairs is IMPORTANT, because we distinct between the delegate and alternate.